The present invention relates to a safety binding for a ski, tripping of which for the release of the boot is controlled by a signal coming from an electrical circuit and relates more particularly to means for detecting the stress produced at the time of skiing.
Safety bindings for skis are known which comprise at least one detection circuit followed by a calculation circuit, then a tripping circuit, these three circuits being supplied by a supply circuit. In this type of binding, the detection circuit detects the stresses due to skiing and is generally in the form of a bridge of gauges. This detection circuit produces a signal dependent on the stress occurring at the time of skiing, which signal is processed by the calculation circuit, which may be a filter for example. This calculation circuit thus emits a signal which is compared with a predetermined value in a threshold circuit which, if this threshold is exceeded, sends a tripping order to the tripping circuit which facilitates the release of a locking member and thus the release of the ski boot. In order to take into account lateral and vertical stresses, it has already been envisaged to use two complete circuits each with their own threshold and each tripped independently, these two circuits being different since the stresses to be measured in the two directions are not identical. Another embodiment proposed a detection circuit, calculation circuit and threshold for the vertical, these two circuits being connected to an OR-gate connected to a single tripping circuit.
Nevertheless, this type of construction has certain drawbacks, since the circuits are different and are produced with different components, which involves high manufacturing costs and numerous risks of errors in the assembly. In addition to the electrical disengagement, there is a mechanical disengagement and the mechanical parts are numerous, which naturally causes high manufacturing costs and clearances or friction may cause errors. Therefore, these systems are not reliable.